Inclined lifts in a great variety of constructions have been proposed heretofore for transferring both lading and persons between different levels. Representative of the prior proposals are the disclosures in the following U.S. patents: Crispen U.S. Pat. No. 1,473,813; Crispen U.S. Pat. No. 1,535,105; Wood U.S. Pat. No. 1,838,204; Wood U.S. Pat. No. 1,933,131; Miller U.S. Pat. No. 2,563,260; Mazzarelli U.S. Pat. No. 3,121,476; Flinchbaugh U.S. Pat. No. 3,662,859; Pulo U.S. Pat. No. 3,749,202; Cheney U.S. Pat. No. 3,966,022; Ackerman U.S. Pat. No. 4,043,427; Flinchbaugh U.S. Pat. No. 4,046,226; and Wilson U.S. Pat. No. 4,050,546.
These prior constructions are substantially equally divided between those having passenger lifts restricted to one side of a stairway and those extending entirely across the stairway thereby precluding use of the stairway by foot traffic while the lift is in use. Both types are subject to serious shortcomings, disadvantages and pose serious hazards and risks both as respects passengers on the lift and foot traffic endeavouring to use the stairway with or without awareness that the lift is in use. A major need for stairway passenger lifts is to accommodate the infirm, the disabled and the incapacitated. In many instances such persons have infrequent need for transport between two levels whereas the majority of occupants of the premises wish to use the stairway conventionally. Prior to this invention there has been no reliable fool-proof and satisfactory combined stairway and power lift meeting the exacting requirements of both types of traffic and suitable for installation either as original building equipment or later as an adjunct.